Cooling system



H. H. BOYCE.

COOLING SYSTEM. APPLICATION FILED NOV. I7, 1916.

1 106,922. Patented Feb. 14, 1922.

i 2 SHEETSSHEET 1- ATTORNEY H. H. BOYCE.

COOLING SYSTEM- APPLICATION FILED NOV. I7, 1916.

Patented Feb. 14, 1922v 2 SHEETS-SHEET 2.

lA/VE/VTOR N. 5.1

M ATTORNEY peratures are reached conditions, while,

cessive degree.

HARRISON H. BOYCE, OF FOREST HILLS, NEW YORK.

COOLING SYSTEM.

Specification of Letters Patent.

Patented Feb. 14, 1922.

Application filed November 17, 1916. Serial No. 131,841.

To all whom it may concern:

Be it known that I, HARRISON H. BOYCE, a citizen of the United States, residing in Forest Hills, county of Queens, and State of New York, have invented certain new and useful Improvements in Cooling Systems, of which the tion.

This invention relates to cooling systems such as are employed in connection with internal combustion engines to prevent the engine cylinders becoming heated to an ex- In internal combustion engines, the combustion of the fuel takes place in the cylinders and very high temand the cooling of the cylinders is, therefore, essential. The most common method of cooling as applied particularly to the engines of automobiles, aeroplanes and the like, consists in the use of jackets around the cylinders, a radiator and connecting pipes, water being circulated through the jackets and radiator. Such systems can be made to cool very effectually but owing to variable outside temperature conditions and other causes, it is not possible with ordinary systems to maintain the engine at all times at the most satisfactory temperature. While cooling is essential, it is nevertheless true that up to a certain point an internal combustion engine will operate more flexibly and with higher efficiency hotter it is. It is, therefore, desirable to maintain the engine at all times as'near a fixed and predetermined high temperature as is possible. It is an object of my invention to accomplish or approximate this result by increasing the cooling effect when temperature conditions are high and decreasing it when the engine is too cool.

Two classes of cooling systems are now in extensive use, in one of which the water is caused to circulate through the system by a pump driven from the engine and in which the circulation of water is positively induced but is entirely independent of temperature in the other system, known as the thermo-siphon system, the circulation is maintained by the difference in weight due to difference in temperature in the columns of water in the cylinder jackets and radiator respectively. The thermosiphon system possesses the advantage that the rapidity of circulation of the water and therefore the cooling effect are dependent in some degree upon temperature conditions, so

following is a specifica-V the e that the system is to a certain extent regulated automatically, the circulation being generally speaking more rapid when the engine is hot and slower when the engine is cool. Thermo-siphon systems, however, are not positive in action and in hot weather or in the case of large engines, it is often difiicult to secure a sufliciently rapid circulation to maintain a proper degree of cooling. The engine therefore runs too hotand is in danger of overheating. Furthermore, in an effort to take care of such extreme conditions of heat, the parts of the system have to be made excessively large, thus increasing the cost of manufacture. invention contemplates a. combination of two systems, securing the advantages and eliminating the defects of both and also securing an automatic control of temperature conditions, tending to promote a uniform temperature of the engine at all times.

In the accompanying drawings which form a part of this specification, I have illustrated certain preferred embodiments of my invention in order to make clear the nature thereof a-ndthe principles underlying its operation. 'In these drawings, Figure 1 is a diagrammatic view showing a part of an internal combustion motor of a type com monly employed on automobiles and show- Re ferring to the drawings in detail and particularly to Figures 1 and 2, the numeral 1 designates the engine having cylinder jackets 2 around the cylinders thereof. 3 is the radiator which may be of any suitable construction. The water heated in the cylinder jackets by contact with the outside of the cylinders is carried to the radiator by means of a manifold 4 and a return pipe 5, the radiator and its pipe connections are of such character and arrangement that the return pipe enters the radiator below the normal water level therein so that under proper conditions a thermo-siphon circulation may be set up. The cooled water leaves the bottom of the radiator through a connection 6 and passes. into a casing 7, which is connected to the cylinder jackets by an inlet pipe 8. The casing 7 contains a'pump chamber 9 in which is mounted a pump l0,which may be of any suitable construction, it being illustrated as of the centrifugal type mounted upon and driven by a shaft, 11, which receives power from the engine and which in the construction shown revolves Whenever the engine is running. The casing 7 also contains two ducts 12 and 13, the first of which is designed to admit water to the central part of the pump chamber, the water being thrown out by the rotation of the pump and discharged through the opening 14 at the top of the chamber into the inlet pipe 8. At the mouthof the'duct 12 is a valve seat 15. The duct 13 affords direct communication from the chamber 7 to the inlet pipe 8, the opening to the duct being provided with a valve seat 16. A valve 17 is adapted to seat upon either of these valve seats 15 or 16, so as to close communication through either the duct 12 or the duct 13. Suitable means for controlling the movements of the valve 17 are provided, these preferably being thermostatic in their nature, so that the movements of the valve will be automatically controlled by the temperature of the cooling water. As illustrated, the valve is mounted on a stem 18, which is connected to the thermostat 19 comprising a drum of corrugated metal filled with an expansible fluid. Any other suitable thermostatic or temperature responsive valve-controlling means may, however, be employed.

In the operation-of the structure described, it will be seen that when the cooling water 1s at a comparatively low temperature, as when starting up the motor, the thermostat will be contracted and the valve will be seated upon the valve seat 15 as shown in F gure 2. This will close the duct 12 and Wlll prevent the passage of the water through the pump so that the pump will have no effect upon the circulation of the water, but merely revolve idly in its chamber. The only passage for the circulating water will, therefore, be through the duct 13 and whatever circulation takes place will be caused by the difference in the temperature of the water surrounding the jackets. and the water in the radiator so that the cooling system will operate as a thermo- S1pl101'1 system. The system will continue to so operate so long as the temperature of the water remains sufficiently cool. When conditions become such,@ however, that the rapidit of circulation thermally induced. is 1nsu cient to effect a proper cooling then the heated water will cause the thermostat 19 to expand, thus lifting the valve 17 front the seat 15 and permitting water to flow through the duct 12 to the pump which will force it into the inlet pipe, thus increasing the rapidity of circulation. The rise in temperature may be sufiicient to cause the valve to close against the seat 16, whereby all of the water will be circulated by the pump or the valve may occupy an intermediate position resulting in a circulation artly forced and partly thermo-siphon. fVhenever owing to therapidity of circulation caused by the pump, the engine and consequently the cooling water becomes too cool, the thermostat will actuate the valve so as to cut down the amount of water going through the pump, thus again de creasing the rapidity of circulation. In this way it will be seen that the system is caused automatically to take care of temperature variations and will tend at all times to maintain the cooling water at a constant temperature. The benefits of a thermosiphon circulation are obtained when temperatures are not high and at the same time a positive circulation is available to take care of more extreme conditions. Owing to the fact that the pump circulation is available, the inlet and outlet pipes, cylinder jackets and radiator need not be of the large proportions which would be necessary to produce the maximum cooling effect if a simple thermo-siphon action were relied upon.

Referring to Figure 3, I have here shown a modified construction for carrying out my invention, in which the water at all times passes through the pump chamber 9, entering the same through the ports 20 from the radiator connection 6 and leaving the chamber through the inlet pipe 8. In this construction, the pump is not positively driven by the engine at all times. Thermostatic or temperatureresponsive means are provided which permit the pump to be partially or wholly inactive when the water is too cool. As illustrated, the pump 10 is arranged to be driven from the shaft 11 through a frictional or slipping clutch connection 21. This connection comprises in the construction illustrated a flange 22 on the end of the shaft 11, a flange 23 on the hub of the pump and washers 24; of suitable frictional material between the flanges. The pump is adapted to be forced against the end of the shaft by a thermostat 19 which may be of any suitable construction such as that already described. When the water is cool, the thermostat contracts and draws the pump away from the end of the shaft so as to relieve the pressure between the flanges 22 and 23, thereby permitting the pump to slow down or stop altogether. At low temperatures, the pump will be en tirely inactive and whatever circulation is set up in the system will be of a thermosiphon character, the water merely flowing through the pump chamber without being accelerated by the pump. At higher temperatures the thermostat 19 will expand thus forcing the flange 23 towards the flange 22, which will result in the pump being rotated by the shaft 11. The rotation of the pump will at once set up a positive circulation of the cooling fluid, increasing its rate of circulation and thereby the cooling effect.

In Figure 4, I have shown another modified construction embodying my invention in which, as in the construction shown in Figures 1 and 2, the pump 10 is constantly driven by the shaft 11. .The pump chamber 9 is also in communication at all times with the interior of the casing 7 through the duct 25 and is also in communication with the inlet pipe 8. A b y-pass 26 around the pump is provided, however, access to which'is through a port 27, controlled by a valve 28, the latter being actuated by a thermostat 19 or in any other suitable manner. When the water is cool, the thermostat 19 contracts, thus opening the valve 28 as shown in Figure 4. This permits the water to flow around the pump instead of through the same and the circulation of the water will, therefore, be chiefly due to thermosiphon action. \Vhen the water heats up, however, the thermostat 19 will expand thereby closing the valve 28 and causing all of the water to flow through the pump. This as explained will increase the rapidity of the circulation and thereby the cooling effect. control exemplified in Figure 3 with a bypass arrangement, as exemplified in Figure 1 or Figure 4, may be employed ifdesired. While I have shown in the drawings and described in detail certain preferred embodiments of my invention, these are to be understood merely as illustrative of the best 7 modes now known to me for practicing the same and I do not intend, therefore, to limitmyself to such embodiments, but intend to cover the principle of my invention broadly in whatever form it may be embodied.

Having thus described my invention, I claim:

1. In apparatus of the character described, the combination with a cooling system of an internal combustion engine designed to provide for a thermo-sipho-n circulation of the cooling fluid, of a mechanical pump for positively circulating the fluid through said system, and means for regulating the relative effects of the thermo-siphon action and of the pump.

2. In apparatus of the character described; the combination with a cooling system of an internal combustion engine designed to provide a thermo-siphon circulation of the cooling fluid, of means for positively circulating the fluid through said system, and

A combination of the methods of the combination with a cooling system means responsive to the temperature of the 3. In apparatus of the character described,

the combination with the coolingsystc-m of an internal combustion motor designed to provide for a thermo-siphon circulation of the cooling fluid caused by the heat of the motor, of mechanically operated means for causing a forced circulation of the fluid through said system, and control means for determining the character of thecirculation. I

4. The combination with the cooling system of an internal combustion motor, of mechanical means capable of producing a forced circulation of the cooling fluid therethrough of sufficient rapidity to cool the motor, and means for rendering said forced circulation means inoperative to produce such circulation, the cooling system being of such a character as to permit of a thermosiphon circulation of the cooling fluid to cool he motor when said forced circulation means is rendered inoperative.

5. The combination with the cooling sys tem of an internal combustion. motor, of a pump in said system including a movable member adapted to be drive-n by the motor to circulate the cooling fluid through the cooling system, and means for rendering said pump operative or inoperative to produce a forced circulation of the cooling fluid, the cooling system being of such a character as to permit a thermo-siphon circulation of the cooling fluid to cool the motor when the pump is rendered inoperative.

6. In apparatus of the character described, the combination with a cooling system designed to provide for a thermo-siphon circulation of the cooling fluid, of a mechanical pump for positively circulating the fluid through said system, and control means for rendering said pump operative or inoperative to produce a forced circulation of the cooling fluid.

7. In apparatus of the character described, the combination of a cooling system, a pump therein for forcing the cooling water to circulate in said system, and thermostatic means for opening a passage around said pump.-

8. In apparatus of the character described,

designed to provide for a thermo-siphon circulation of the cooling fluid, of a mechanical pump for causing the fluid to circulate in said system, and thermostatic means for controlling the operation of said pump.

9. In apparatus of the character described, the combination with a cooling system, of a pump for circulating the water in said system, a by-pass around said pump, a valve for opening and closing said by-pass and temperature responsive means for actuating said valve.

10. In apparatus of the character described, the combination of a cooling system, a pump in said system, a passage communicating with the inlet side of said pump,

a by-pass around said pump and a valveadapted to control the passage tosaid pump 10 and said by-pass.

11. In apparatusof the character described, the combination of a cooling system, a pump in said system, a passage communicating with the inlet side of said pump, a by-pass around said pump, a valve adapted to control the passage to said pump and said by-pass, and a thermostat arranged to be) influenced by the temperature of the cooling fluid for actuating said valve.

HARRISON H. BOYCE. 

